I’d post a reply but I don’t understand the OP.
I think I get it: they’re saying that instead of the early Earth just getting a little messed up by planetesmal impacts, it was in effect completely re-melted and the chemical composition of the molten rock completely rearranged.
I’m sure I’m seen theories based on that somewhere before, though.
Ice Wolf, you’re right about the general concept having been around for some time. What’s different, according to this study, is the time frame involved - all the melting and subsequent chemical differentiation of the different layers of the Earth would have happened in just 30 million years’ time, rather than over 100-200 million years (which was the thought previously). That brief span is what requires the amalgamation of planetismals to accumulate in a more “violent” fashion.
Personally, I don’t think violent is really the right word here, because I think what the scientists are implying is that the planetismals struck infant Earth more often and consistently, not that the impacts themselves were harder… but it is a press release, and the “violent” is certainly evocative.
I don’t see why this is such a big surprise. If scientist’s would’ve just asked around, they would’ve known this sooner. Mars, for instance, is always going on about how Earth used to beat it up back in elementary school …